Microscopes
* Increasing the objective lens focal length: *Decreases* magnification. A longer focal length objective lens captures a wider field of view, but the image appears smaller.
* Increasing the eyepiece lens focal length: *Increases* magnification. A longer focal length eyepiece magnifies the image produced by the objective lens more.
Telescopes
* Increasing the objective lens focal length: *Increases* magnification. A longer focal length objective lens gathers more light and produces a larger image, resulting in greater magnification.
* Increasing the eyepiece lens focal length: *Increases* magnification. Similar to microscopes, a longer focal length eyepiece further magnifies the image produced by the objective lens.
Key Points
* Magnification is a ratio of the image size to the object size.
* Focal length is the distance between the lens and the point where light rays converge to form an image.
Example:
Imagine a microscope with an objective lens of 10mm focal length and an eyepiece of 10mm focal length. The magnification would be roughly 10x (objective lens magnification) multiplied by 10x (eyepiece magnification) = 100x.
If you were to increase the objective lens focal length to 20mm, the magnification would decrease to 50x. However, increasing the eyepiece focal length to 20mm would increase the magnification to 200x.
Summary:
* Microscopes: Longer objective lens focal length = *lower* magnification; Longer eyepiece focal length = *higher* magnification.
* Telescopes: Longer objective lens focal length = *higher* magnification; Longer eyepiece focal length = *higher* magnification.
